Unit 1 Friendship reading 课时作业

　　A

　　Charlie studied chemistry in a famous college for four years.He studied hard and did well in all his subjects.He hoped to become a good teacher.This year he left the college and began to work in a middle school.He liked his students and was strict with them.He did his best to make his classes lively and interesting so that his students could learn chemistry well.

　　One day he carefully explained a chemical reaction (化学反应) to the students of Grade Two in the chemistry lab，hoping they can understand the reaction completely.

　　"Be careful，everyone，"he said loudly."Before I make the experiment，there are 25 atoms of carbon (碳原子)but after I finish it，there are 24 atoms of carbon left！"

　　He stopped to watch the classroom and hoped his students would go on explaining it.But the young men looked at each other and nobody answered him.He had to ask，"What happens？" "What makes the atom disappear？"

　　The lab was very quiet and none of the students looked at their teacher.

　　"Who can tell us where it has gone？"

　　Suddenly a soft voice came from the back row，"We did not see anybody leave the lab！"

　　1．Charlie began to work in the middle school because ________．

　　A．he had been in the school for only four years

　　B．he couldn't do anything except teaching

　　C．he hoped to become a good teacher

　　D．he did well in all his subjects

　　2．Charlie hoped ________，so he did his best to make his classes lively and interesting.

　　A．all his students could do the experiment by themselves

　　B．his students wouldn't be afraid of him

　　C．his students could carefully watch him making the experiment

　　D．his students could do well in chemistry

　　3．Charlie wished his students could ________．

　　A．learn the chemical reaction B．find the atoms of carbon

　　C．count the atoms of carbon D．make the experiment

　　4．The students couldn't answer Charlie's questions because ________．

　　A．none of them had seen the atoms

　　B．they didn't understand their teacher

　　C．the chemical reaction was complicated(复杂的)

　　D．they all disliked the subject